Switch mechanism



Ap 7, 1931- w. H. SCHRAMM SWITCH MECHANISM Filed May 26, 1927 V HUHdTllllLlllll. W

INVENTOR Walter H. Schramm AT'IFORNEY Patented Apr. 7, 1931 UNITEDSTATES PATENT OFFICE WALTER H. soHRAMivr, or PITTSBURGH, PENNSYLVANIA,ASSIGNOR 'ro WESTING- HOUSE ELECTRIC & MANUFAOTURING ooMPAnxnCORPORATION or PENNSYL- VANIA Application filed May 26,

My invention relates to switch mechanism and particularly toback-of-board switchboard type switches wherein the switch mechanism ismounted behind a dead front switchboard or panel.

An object of my invention is to provide a back-of-board type switchmechanism that is directly operated from the front of the board by meansof an operating handle directly connected to the switch blade andwherein the operating handle is disposed within a recess in the frontplate of the switchboard and lies behind the front plate when in theclosed position.

Another object of my invention is to provide a switch mechanism havingthe above noted characteristics wherein the fuse associated with theswitch is accessible through an opening adjacent to the recess in theswitchboard, the opening being closed by a detachable cover and whereinthe fuse mechanism is rendered inaccessible so long as the switch is inany other than full open position.

Another object of my invention is to provide a switchboard of theback-of-board type that is relatively simple in construction and iscomposed of a relatively small number of arts.

p Heretofore switchboards of the back-of-' board type usually comprisedknife switches having an operating handle pivoted to the switchboard andindirectly connected to the switch in such manner that it may beactuated by movement of the handle.

Another object of my invention is to provide a switchboard apparatus ofthe back-ofboard type wherein the operating handle is mounted on thebase carrying the switch and which is directly connected thereto andwherein the handle lies within a recess in the switchboard face when theswitch is in closed position.

These and other objects that will be made apparent throughout thefurther description of my invention, are obtained by means of theswitchboard apparatus hereinafter described and illustrated in theaccompanying drawings wherein;

Figure 1 is a front view ofa switchboard swrrcn Mn'cnnmsm 1927. SerialNo. 194,246.

pagel embodying features of my invention, an i Fig. 2 is a verticalsection through the apparatus shown in Fig. 1 taken on the line II- IIof Fig. 1.

Referring to the drawings, the apparatus includes a front plate or panelsection 3 made of sheet metal and which constitutes a front face orplate of the switchboard. Itwill be understood that in the usual metalswitchboard construction, the panels such -as the panel 3 are joined attheir edges to constitute a complete switchboard. The panelor frontplate 3 is provided with a pair of openings 4 and 5, the lowermost beingrectangular and the uppermost being of inverted T-shape. Theupper recess4 is closed by means of a cover 6 provided with a recess or pocket thelower wall 8 of which is arcuate in shape and is provided with a keyholeslot 9 having enlarged end portion 10, the purpose of which willhereinafter appear.

Behind the front plate 3 of the switchboard, an insulating panel 11 ismounted. The'panel 11 may be secured to the frame upon which the frontplate is mounted or may be carried upon brackets attached to the frontplate'as preferred. Upon the panel is mounted a set of contact jaws 12and a set of pivoted jaws 13 in which a set of switch blades 1A arepivotally'mounted for rotation about a pivoted shaft 15- which ismounted concentric with the center of curvature-of the arcuate wall 8 ofthe closure plate 6.

As illustrated,-the switch is of the 3 pole type, and the blades thereofare connected at their free ends by an insulating cross bar 16 uponwhich an operated handle 17 is secured at the center thereof. The handleprojects through the slot 9 and as illustrated in Fig. 2, occupies aposition within the recess 7 and behind the front plate of the panelwhen the switch is in the closed position illustrated in Fig. 2. Thelower end of the slot 9 is enlarged at 10 to permit of the assembly ofthe switch with respect to the front plate. It will be understood thatthe switch mechanism is assembled upon the insulating panel 11 before itis finally located in its permanent position. -During the assembly, theoperating handle is first moved to full open position and insertedthrough the enlarged end of the opening.

Fuses 18 are mounted in receptacle clips 19 that are secured to theinsulated base 11, the fuses registering with the opening 5 in the panelplate 3 and are, therefore, accessible through the said opening.

The opening 5 is closed by a cover plate 21 that is detacl'iablyretained in closed position by means of clips 22 secured adjacent thelower end of the cover plate and which extend behind the cover plate insuch manner that they engage the lower edge of the opening and preventdisplacement of the cover. The upper edge of the cover 21 is retained inclosed position by clips 23 that are engaged by a pair of pivotedlatches 24 carried by the front plate or panel 3.

The latches 24 are actuated by gravity into the position in front of theclips 23 and prevent detachment of the cover 21 while in such position.The upper ends 25 of the latches 24.- are inclined toward one anotherand are adapted to be engaged by the insulating cross bar 16 of theswitch when the latter is in the full open position indicated in dottedlines in Fig. 2.

When the switch is in the full open position, the latches 2d are movedto the broken line position indicated in Fig. 1 wherein the lower endsthereof disengage from the clips 23 on the cover 21 and permit ofremoval of the cover plate. By reason of this interlocked constructionof the switch and door,

the door closing access to the fuses is retained in the closed positionso long as the switch is in any position, other than the full openposition.

When the switch is in the closed position, the handle 17 thereof doesnot extend beyond the front face of the board, and therefore cannot beengaged by foreign articles which may be brought into contact with theswitchboard face. Since the handles project in front of the board whenthe switch is open the handles indicate the position of the switch. 7

As previously stated, it has been customary to provide auxiliary leversfor operating back-o-f-board type of switches, the operating handlebeing pivotally connected to the switch plate. By reason of the presentconstructio'n, the operating handle may be directly connected to theswitch blade, thus eliminating several parts heretofore found to benecessary and thereby correspondingly reducing the cost of manufacture.A further advantage of this type of switchboard apparatus resides in thefact that the operated handles lie within the recesses when the switchesare in closed position.

It will be understood that the system embodying my invention is notlimited to the specific arrangement of parts shown in the drawings anddescribed in the foregoing specification, as many changes andmodifications may be made therein without departing from the spirit andscope of my invention, as set forth in the appended claims.

I claim as my invention:

1. Switch mechanism comprising a front plate having a perforate pocketin the front face thereof extending behind the front face of the plate,a knife switch pivotally maintained behind the front plate and having anoperating handle extending into the pocket and lying behind the frontface of the front plate when the switch is in closed position.

2. Switch mechanism comprising a front plate having a pocket extendingbehind the front face of the plate provided with an arcuate' wall havinga slot therein, a knife switch pivotally mounted behind the front plateand having an operating handle extending into the pocket and lyingbehind the front face of the front plate when the switch is in closedposition.

3. Switch mechanism com-prising a frontpl'ate having a perforate pocketin the front face thereof extending behind the front face of the plate,a knife switch pivotally mounted behind the front plate and havin anoperating handle extending into the pocket and lying behind the frontface of the front plate when the switch is in closed position andproject-ing in front of the front face of the front plate when theswitch is in open position.

4:. Switch mechanism comprising a front plate having an opening therein,a cover plate for the opening having a recess extending behind the frontface of the plate and provided with a perforation, a switch mountedbehind the front plate and having an operating handle extending throughthe said perforation into the recess, the said handle lying behind thesaid front plate when in closed position and extending in front of thesaid plate when the switch is closed.

In testimony whereof, I have hereunto subscribed my name this 24zth dayof May, 1927.

lVALT-ER H. SCHRAMM.

